The present invention relates generally to electric appliances for heating liquids and more specifically to an electric appliance for rapidly heating and dispensing a small quantity of water for making instant beverages, tea, coffee, soup and the like. The invention relates to a novel valve construction for use in connection with such an appliance. The disclosed appliance and valve construction represent improvements over the appliances disclosed in the Augustine, et al. U.S. Pat. No. 3,878,360 and Beckering, et al. U.S. Pat. No. 4,614,859.
The objective or function of an appliance of the type with which the invention is concerned is to heat a small quantity of water on the order of sixteen ounces to a boiling temperature in a relatively short period. By employing a relatively high wattage heating element on the order of 1000 to 1400 watts, it is possible to heat the water contained therein to 197.degree. F. and dispense it in a period of less than two minutes.
The appliance is designed to provide a signal when the contents have been heated to the boiling point, at which time the operator may manually operate a valve to dispense the hot water into a waiting receptacle. The dispensing valve must be associated with the heated container in order that the dispensing of the heated contents may be done simply and effectively. Because of the high temperatures associated with the reservoir in which the water is heated and the likelihood of frequent cycling every day during repeated use the demands on the dispensing valve are quite high. The valve must be designed so that it will operate with a minimum amount of force and will continue to operate without any leakage over a substantial period of time. Because of the moist and high temperature environment, metal parts which are exposed to water and then dried quickly have a tendency to rust and seal improperly, and plastic parts have a tendency to deform from the heat. It is also necessary that conduit means be provided to deliver the water from the bottom of the heating vessel to an area outside of the housing in which the heating vessel and its associated electrical components are enclosed. The conduit must be well sealed to avoid any possible leakage in the vicinity of the electrical connections within the housing.
There are known in the prior art various types of valve and conduit combinations which are used primarily in connection with dispensers associated with bottles containing various types of liquids. In some of these prior art valve and conduit patents there are flexible conduits which may be deformed to displace valve members associated therewith. Examples of these prior art patents are Miller U.S. Pat. No. 549,678, Miller U.S. Pat. No. 3,151,787, Henricson U.S. Pat. No. 2,543,850, Gunn U.S. Pat. No. 1,992,067 and Bross U.S. Pat. No. 3,193,154. None of these prior art valves are of a construction that would be suitable for associating with an electric appliance of the type with which the present invention is concerned.